Makes the current page dim out when transitioning to instant preview.

chrome/browser/ui/browser.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_BROWSER_H_
 #define CHROME_BROWSER_UI_BROWSER_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 755 matching lines @@
 
   // Overridden from NotificationObserver:
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   // Overridden from ProfileSyncServiceObserver:
   virtual void OnStateChanged();
 
   // Overriden from InstantDelegate:
+  virtual void PrepareForInstant();
   virtual void ShowInstant(TabContents* preview_contents);
   virtual void HideInstant();
   virtual void CommitInstant(TabContents* preview_contents);
   virtual void SetSuggestedText(const string16& text);
   virtual gfx::Rect GetInstantBounds();
 
   // Command and state updating ///////////////////////////////////////////////
 
   // Initialize state for all browser commands.
   void InitCommandState();
@@ skipping 299 matching lines @@
   // The profile's tab restore service. The service is owned by the profile,
   // and we install ourselves as an observer.
   TabRestoreService* tab_restore_service_;
 
   scoped_ptr<InstantController> instant_;
 
   DISALLOW_COPY_AND_ASSIGN(Browser);
 };
 
 #endif  // CHROME_BROWSER_UI_BROWSER_H_